What Types of Letters Are Used in Affidavits?

Letter of Personal Knowledge

• Affidavits are all letters of personal knowledge; they may be written opinions, eye-witness testimonies or professional evaluations. They will list the author's name, background, relationship to the case, and the reason behind the writing. They will be told in first-person narrative and have listed at the top the case to which they are relevant. All will be certified as truth to the best of the writers' knowledge.
  
  

Letter of Opinion

• Some judges will allow letters of opinion or personal references to be admissible in cases such as custody or civil litigation. These letters must clearly state the author's relationship to the person referred to and state that they are letters of opinion and not fact. The judge or jury reading the letter will then weigh in any personal prejudices that the author may have had on behalf of the person referenced in the letter.
  
  

Eye-Witness Testimony

• In many cases where the eye-witness cannot attend the trial (the witness may live across the country, for example), the judge may allow testimony in affidavit form. This is entirely dependent upon the reasons why the witness cannot be present and whether the judge allows affidavit testimony. Affidavits taken at the time of witness can also be used in conjunction with verbal testimony at the time a trial occurs.
  
  

Expert Testimony

• In many cases, especially criminal, testimony from scientists who are considered experts in their field is offered in affidavit form. This may be done because the scientist's schedule prohibits him from attending the trial or because of his location. The affidavit will contain the scientist's background credentials, any tests he conducted for the trial (such as ballistics or handwriting analysis), and his expert opinion as to the circumstances of the case.